This is very straightforward. Talk to Rytlock in his office to learn that the charr High Legions would like to study one of the amulets which a necromancer called Rissa has been giving many different people. It is believed those amulets are attracting undead. Rytlock has heard that your deceased friend, Howl the Brazen, possessed such an amulet, and would like you to retrieve it from his grave in the Plains of Ashford. He explains that the three Orders of Tyria are sending a representative to help you.

Next, you'll be in the company of one charr member of each of the three orders. After listening to a short conversation between themselves, a cutscene will play where they will introduce themselves to you. You'll have to kill the Risen Grubs near Howl's grave to get his amulet from there. After examining the grave and discovering that Howl's body is gone together with the amulet, the Vigil representative and the Order of Whispers agent will suggest what they think you should be doing next: Defend Snowdrift Haven from the risen attack it is currently undergoing and get an amulet that is known to be there, or go and get an amulet from the norn Klaes in Durgar's Homestead which is risking an imminent attack as well.

Choose either the Vigil's or the Order of Whispers' plan. This will give you an idea of how the different orders operate, which will help you later on when the time comes to choose an order to join.

In recognition of your exemplary performance to date, your legion has promoted you to centurion.Congratulations, soldier.But don't celebrate too hard. This isn't a ceremonial promotion: higher rank means higher expectations, more responsibility, and more important duties.Starting now: I have your first assignment waiting. Report to me in my office as soon as possible for your orders.On a more personal note, let me say how glad I am to have another fighting soldiers among the brass.Welcome aboard.

Rytlock called me in to promote me to centurion and to give me a new assignment: the orders of Tyria are on the trail of a necromancer called Rissa. Rissa may have infected my fallen comrade, Howl the Brazen, so Rytlock wanted me to be involved, and to join the order reps at Howl's grave.

I met with representatives of the Vigil, the Order of Whispers, and the Durmand Priory at Howl's grave. There was no body, but there was a swarm of undead grubs. Someone took Howl's body and the necromancer's amulet he was buried with, so I decided to work with one of the orders to find out who did it and why and to make sure they suffer for trifling with my warband.